Fuel-feed valve and valve-operating mechanism for internal-combustion engines.



F. W. LANCHESTER. FUEL FEED VALVE AND VALVE OPERATING MECHANISM FORINTERNAL COMBUSTION ENGlNE S-.

APPLlCATl0N FlLED OCT. 30. 19n.

1,274,059. A Patented July-30, 1918.

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F. ..W. LANCHESTER.

F'UEL FEED VALVE AND VALVE OPERATING MECHANISM FOR INTERNAL COMBUSTIONENGINES.

APPLICATION FILED on; so, 1911.

1,274,059. Patented Jul 0,1918.

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E I INVENTOR E Fzed rzclii Lanckeeien ATTORN EYSP UNITED STATES PATENTOFFICE.

FREDERICK WILLIAM LANCHESTER, OF LONDON, ENGLAND.

FUEL-FEED VALVE AN D VALVE-OPERATING MECHANISM FOR INTERNAL-COMBUSTIONENGINES.

Specification of Letters Patent.

Patented July 30,1918.

Application filed October 80, 1917. Serial No. 199,390. A I

To all whom it may concern:

Be it known that I, FREDERICK WILLIAM LANCHESTER, a subject of the Kingof Great Britain and Ireland, and residing at 41 Bedford Square, London,IV. C. 1, England, have invented certain new and useful Im-. provementsin Fuel-Feed Valves and Valve- Operatin Mechanism forInternal-Combustion ngines, of which the following is a specification.

The present invention relates to improvements in fuel feed valves forinternal combustion engines and refers more especially to an improvedtype of valve and valve operating mechanism for internal combustionengines of the high pressure self-ignition type.

In high pressure engines of the Diesel or self-ignition type asheretofore constructed the fuel has been admitted by a timedcamoperatedvalve allowing the liquid fuel to pass under high pressure toa fine jet or jets giving admission to the combustion space. In somecases air under pressure is admitted simultaneously with the liquid fuelor the latter is blown in by highly compressed air froma passage orrecess into which it has been previously injected; in other cases thefuel is sprayed under its own presure.

The present invention relates to improve ments in fuel valves and fuelvalve gears of the type in which the valve is opened by impact, suchtype being more especially applicable to engines in which auxiliary airis not employed. The volume of liquid fuel to be injected into thecylinder at each stroke is relatively very small; and such volume, whenthe flow takes place under constant pressure, depends on three factors,viz., the difference between the pressures of the oil in the supplychannels and of the pre-compressed air in the cylinder, (which affectsthe velocity of efllux of the oil), the effective area of the valveopening, and the time during whichthe valve remains open. The velocityof eillux is necessarily great; with the usual type of cam-operated fuelvalve the time during which the valve is held open is relatively long,and therefore the effective area of opening must be kept very small. Theusual type of fuel admission/ device is,a needle valve. It has beenproposed to use a needle valve held down on its seat by spring pressure,and opened by the impact of a striker released at the proper intervalsby timing mechanism the impact of the striker being transmitted to theneedle valve by means of abell-crank lever. The impact effect of ahammer blow is however, more or less dissipated if transmitted throughan elastic member like a bell-crank lever, and this type of constructionis avoided in the present invention.

In some cases a fuel measuring pump is employed, the object being tomeasure oil a definite volume of fuel to be discharged into the cylinderat each stroke of the engine piston. Owing, however, to the large volumeof the passages from the fuel measuring pump to the pointof dischargeinto the cylinder, as compared with the measured volume, the amount ofoil delivered to the cylinder may vary considerably from stroke tostroke, and the device fails to give the desired result. 7

The presentinvention consists in opening the fuel valve by thedirect'impact of a suitably timed hammer or tup which strikes the valvestem or a piece rigidly fastened thereto.

The invention also consists in closing the valve by means of the fuelpressure acting differentially on the plunger or valve stem, so that thevalve under fuel pressure tends to remain closed.

The invention further consists in an improved fuel valve arranged toopen direct into the cylinder or combustion space, in which the lips ofthe valve and seat form the injection nozzle.v

The invention further consists of means,

independent of the means for timing the hammer blow, for varying theeffective impulse of the blow whereby the time during which the valveremains open can be regulated as the load on the engine varies.

The invention also consists in combinations of the above devices.-

Referring to the accompanying sheet of illustrative drawings Figure 1 isa section through a fuel valve and mounting. constructed in accordancewith the present invention; the plane *of Fig. '3 representsdiagrammatically a pneumatic pump and timing device suitable foractuating the pneumatic device aforesaid by means of which the hammeror' tup. is caused to deliver its blow. I

In detail reference to the figures, in whichlike letters refer to likeparts throughout, A is the valve head of which the stem A is securelyattached to the ram or balance plunger A of suitably larger diameterthan the effective diameter of the. valve seat. This plunger has formedon it a butt A adapted to be acted upon by impact in the mannerhereinafter described. B is the valve box or mounting having a passage Bfor the supply of liquid fuel admitted under appropriate pressurethrough a supply pipe B and port B. A plug B may be provided to permitof cleaning the passage B and to allow at any time of trapped air beingdischarged in cases where the position of the valve is vertical asshown. A spring A is provided to retain the valve A seated independentlyof the pressure force difference.

The valve unit A 'A A A is so constructed and connected as to constitutevirtually one solid piece; in the example illustrated the valve stem isscrewed into the butt the screw being pegged and grouted with solder.The valve is permitted a small degree of movement only, the greatestpossible opening being limited by the shoulder of the butt portion Amaking contact with the valve boxor lug B The valve unit is actuated bythe impact of a hammer or tup C striking the valve butt A, the saidimpact causing thev valve to lift against the pressure on thedifferential area and the valve spring. The blow thus administeredcauses the valve to jump, the period during which it thus remains openbeing very brief but nevertheless suflicient to permit of the injectionof the fuel under the heavy pressure which is employed in order to sprayor atomize the charge. The tup or hammer C is fitted within the cylinderD and is raised into its topmost position by the spring C All pressureis admitted by a port D at a pre-arranged point of the cycle anapproprlate degree in advance'of the required fuel injection; the airadmitted by D actson the tup C to overcome the spring pressure and givethe required blow. Both the timing of the air admission and the pressureused may be made variable and the means of variation may be placed inthe hands of the driver or attendant, or automatic control may beprovided. The momentum of the blow may be varied by shortening orlengthening the stroke permitted to the tup by means of a screwed stop Darranged to be screwed in or out for this purpose.

Whereas in engines in which the fuel valve is cam operated the time ofopening varies according to (inversely as) the speed of revolution, withmy invention the time the fuel valve remains open, and therefore. theamount offuel delivered to the combustion space at each stroke, isindependent of the speed.

In the form of fuel valve described in the present specification thespraying is more effective than is the case with an ordinary needlevalve. When the latter is employed the fuel passage terminates in thecombustion space as a rose nozzle in which the fuel passes through anumber of finely drilled passages. During the periods when the valve isnot fully opened the fuel is withdrawn and the full fuel pressure is notadmitted to the rose nozzle, the velocity. of efliux is lowandatomization is imperfect.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is 1. An internal engine of the type describedcomprising an engine cylinder having an inlet port, and a fuel supplypassage leading thereto, a normally closed valve controlling said inletport having a valve stem,

a hammer normally retracted from said stem I and arranged to operate onsaid valve stem, and means for actuating said hammer at the proper timesto deliver a percussive blow to said stem.

2. An internal engine of the type described comprising an enginecylinder having an inlet port, and a fuel supply passage leadingthereto, a normally closed valve controlling said inlet port having avalve stem, a butt rigidly carried by said valve stem, a hammeryieldingly pressed away from said butt. andarranged to operate on saidbutt, and means for actuating said hammer to give a percussive blow tosaid butt.

3. An internal'combustion engine of the type specified comprising anengine cylinder having an inlet port and a fuel passage leading thereto,a normally closed valve controlling said port and arranged to open inthe direction of flow of the fuel, and having a suitable stem, a hammer,a spring normally pressing said hammer away from the stem arranged toact on said stem, and means for operating sald hammer to dellver apercussive blow to sald stem.

4:- An internal combustion engine of the type specified comprising anengine cylinder having an inlet port provided with a valve seat facingthe combustion chamber,.a valve within the combustion space cooperatingan inwardly opening valve having a stem provided wlth a part of greaterarea working in said passage, means for conducting fuel under pressureto said inlet between the valve and said part, and a percussive hammerfor operating said valve.

6. An internal engine of the type described comprising an enginecylinder having an inlet port, and a fuel supply passage leadingthereto, a normally closed valve controlling said inlet port having avalve stem, a hammer arranged to operate on said valve stem, and meansfor actuating said hammer signature.

at the proper times, and means for varying the stroke of the hammer.,

7 An internal engine of the type described comprising an engine cylinderhaving an inlet port, and a fuel sup ly passage leading thereto, anormally close valve controlling said inlet port having a valve stem, a.pneumatic percussive hammer arranged to operate on said valve stem, andmeans for actuating said hammer at the proper times.

In testimony whereof I have aflixed my FREDERICK WILLIAM LANGHESTER.

